100-Engine Program Comes in the Wake of the FAA’s New Unleaded Avgas Transition Plan Just a day after the FAA finally laid a real foundation for general aviation’s eventual transition to unleaded avgas, Bushliner Aircraft and DeltaHawk Engines announced a partnership centered on integration of the no-lead-necessary DHK-A6 series engine into the Bushliner 1850. The new production and integration of 100 units of the 350 hp turbodiesel engine.